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x86: arch/x86/mm/init_64.c printk fixes
[linux-2.6/btrfs-unstable.git] / arch / x86 / mm / init_64.c
bloba952726445916012c7c9410bcc6ecdc9f601a2d3
1 /*
2 * linux/arch/x86_64/mm/init.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 * Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
6 * Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
7 */
8
9 #include <linux/signal.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/ptrace.h>
16 #include <linux/mman.h>
17 #include <linux/mm.h>
18 #include <linux/swap.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/pagemap.h>
22 #include <linux/bootmem.h>
23 #include <linux/proc_fs.h>
24 #include <linux/pci.h>
25 #include <linux/pfn.h>
26 #include <linux/poison.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/module.h>
29 #include <linux/memory_hotplug.h>
30 #include <linux/nmi.h>
31
32 #include <asm/processor.h>
33 #include <asm/system.h>
34 #include <asm/uaccess.h>
35 #include <asm/pgtable.h>
36 #include <asm/pgalloc.h>
37 #include <asm/dma.h>
38 #include <asm/fixmap.h>
39 #include <asm/e820.h>
40 #include <asm/apic.h>
41 #include <asm/tlb.h>
42 #include <asm/mmu_context.h>
43 #include <asm/proto.h>
44 #include <asm/smp.h>
45 #include <asm/sections.h>
46 #include <asm/kdebug.h>
47 #include <asm/numa.h>
48
49 const struct dma_mapping_ops *dma_ops;
50 EXPORT_SYMBOL(dma_ops);
51
52 static unsigned long dma_reserve __initdata;
53
54 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
55
56 /*
57 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
58 * physical space so we can cache the place of the first one and move
59 * around without checking the pgd every time.
60 */
61
62 void show_mem(void)
63 {
64 long i, total = 0, reserved = 0;
65 long shared = 0, cached = 0;
66 struct page *page;
67 pg_data_t *pgdat;
68
69 printk(KERN_INFO "Mem-info:\n");
70 show_free_areas();
71 printk(KERN_INFO "Free swap: %6ldkB\n",
72 nr_swap_pages << (PAGE_SHIFT-10));
73
74 for_each_online_pgdat(pgdat) {
75 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
76 /*
77 * This loop can take a while with 256 GB and
78 * 4k pages so defer the NMI watchdog:
79 */
80 if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
81 touch_nmi_watchdog();
82
83 if (!pfn_valid(pgdat->node_start_pfn + i))
84 continue;
85
86 page = pfn_to_page(pgdat->node_start_pfn + i);
87 total++;
88 if (PageReserved(page))
89 reserved++;
90 else if (PageSwapCache(page))
91 cached++;
92 else if (page_count(page))
93 shared += page_count(page) - 1;
94 }
95 }
96 printk(KERN_INFO "%lu pages of RAM\n", total);
97 printk(KERN_INFO "%lu reserved pages\n", reserved);
98 printk(KERN_INFO "%lu pages shared\n", shared);
99 printk(KERN_INFO "%lu pages swap cached\n", cached);
100 }
101
102 int after_bootmem;
103
104 static __init void *spp_getpage(void)
105 {
106 void *ptr;
107
108 if (after_bootmem)
109 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
110 else
111 ptr = alloc_bootmem_pages(PAGE_SIZE);
112
113 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
114 panic("set_pte_phys: cannot allocate page data %s\n",
115 after_bootmem ? "after bootmem" : "");
116 }
117
118 pr_debug("spp_getpage %p\n", ptr);
119
120 return ptr;
121 }
122
123 static __init void
124 set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot)
125 {
126 pgd_t *pgd;
127 pud_t *pud;
128 pmd_t *pmd;
129 pte_t *pte, new_pte;
130
131 pr_debug("set_pte_phys %lx to %lx\n", vaddr, phys);
132
133 pgd = pgd_offset_k(vaddr);
134 if (pgd_none(*pgd)) {
135 printk(KERN_ERR
136 "PGD FIXMAP MISSING, it should be setup in head.S!\n");
137 return;
138 }
139 pud = pud_offset(pgd, vaddr);
140 if (pud_none(*pud)) {
141 pmd = (pmd_t *) spp_getpage();
142 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
143 if (pmd != pmd_offset(pud, 0)) {
144 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
145 pmd, pmd_offset(pud, 0));
146 return;
147 }
148 }
149 pmd = pmd_offset(pud, vaddr);
150 if (pmd_none(*pmd)) {
151 pte = (pte_t *) spp_getpage();
152 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
153 if (pte != pte_offset_kernel(pmd, 0)) {
154 printk(KERN_ERR "PAGETABLE BUG #02!\n");
155 return;
156 }
157 }
158 new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
159
160 pte = pte_offset_kernel(pmd, vaddr);
161 if (!pte_none(*pte) &&
162 pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
163 pte_ERROR(*pte);
164 set_pte(pte, new_pte);
165
166 /*
167 * It's enough to flush this one mapping.
168 * (PGE mappings get flushed as well)
169 */
170 __flush_tlb_one(vaddr);
171 }
172
173 /* NOTE: this is meant to be run only at boot */
174 void __init
175 __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
176 {
177 unsigned long address = __fix_to_virt(idx);
178
179 if (idx >= __end_of_fixed_addresses) {
180 printk(KERN_ERR "Invalid __set_fixmap\n");
181 return;
182 }
183 set_pte_phys(address, phys, prot);
184 }
185
186 static unsigned long __initdata table_start;
187 static unsigned long __meminitdata table_end;
188
189 static __meminit void *alloc_low_page(unsigned long *phys)
190 {
191 unsigned long pfn = table_end++;
192 void *adr;
193
194 if (after_bootmem) {
195 adr = (void *)get_zeroed_page(GFP_ATOMIC);
196 *phys = __pa(adr);
197
198 return adr;
199 }
200
201 if (pfn >= end_pfn)
202 panic("alloc_low_page: ran out of memory");
203
204 adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
205 memset(adr, 0, PAGE_SIZE);
206 *phys = pfn * PAGE_SIZE;
207 return adr;
208 }
209
210 static __meminit void unmap_low_page(void *adr)
211 {
212 if (after_bootmem)
213 return;
214
215 early_iounmap(adr, PAGE_SIZE);
216 }
217
218 /* Must run before zap_low_mappings */
219 __meminit void *early_ioremap(unsigned long addr, unsigned long size)
220 {
221 pmd_t *pmd, *last_pmd;
222 unsigned long vaddr;
223 int i, pmds;
224
225 pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
226 vaddr = __START_KERNEL_map;
227 pmd = level2_kernel_pgt;
228 last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
229
230 for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
231 for (i = 0; i < pmds; i++) {
232 if (pmd_present(pmd[i]))
233 goto continue_outer_loop;
234 }
235 vaddr += addr & ~PMD_MASK;
236 addr &= PMD_MASK;
237
238 for (i = 0; i < pmds; i++, addr += PMD_SIZE)
239 set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
240 __flush_tlb_all();
241
242 return (void *)vaddr;
243 continue_outer_loop:
244 ;
245 }
246 printk(KERN_ERR "early_ioremap(0x%lx, %lu) failed\n", addr, size);
247
248 return NULL;
249 }
250
251 /*
252 * To avoid virtual aliases later:
253 */
254 __meminit void early_iounmap(void *addr, unsigned long size)
255 {
256 unsigned long vaddr;
257 pmd_t *pmd;
258 int i, pmds;
259
260 vaddr = (unsigned long)addr;
261 pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
262 pmd = level2_kernel_pgt + pmd_index(vaddr);
263
264 for (i = 0; i < pmds; i++)
265 pmd_clear(pmd + i);
266
267 __flush_tlb_all();
268 }
269
270 static void __meminit
271 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
272 {
273 int i = pmd_index(address);
274
275 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
276 unsigned long entry;
277 pmd_t *pmd = pmd_page + pmd_index(address);
278
279 if (address >= end) {
280 if (!after_bootmem) {
281 for (; i < PTRS_PER_PMD; i++, pmd++)
282 set_pmd(pmd, __pmd(0));
283 }
284 break;
285 }
286
287 if (pmd_val(*pmd))
288 continue;
289
290 entry = __PAGE_KERNEL_LARGE|_PAGE_GLOBAL|address;
291 entry &= __supported_pte_mask;
292 set_pmd(pmd, __pmd(entry));
293 }
294 }
295
296 static void __meminit
297 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
298 {
299 pmd_t *pmd = pmd_offset(pud, 0);
300 spin_lock(&init_mm.page_table_lock);
301 phys_pmd_init(pmd, address, end);
302 spin_unlock(&init_mm.page_table_lock);
303 __flush_tlb_all();
304 }
305
306 static void __meminit
307 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
308 {
309 int i = pud_index(addr);
310
311 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
312 unsigned long pmd_phys;
313 pud_t *pud = pud_page + pud_index(addr);
314 pmd_t *pmd;
315
316 if (addr >= end)
317 break;
318
319 if (!after_bootmem &&
320 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
321 set_pud(pud, __pud(0));
322 continue;
323 }
324
325 if (pud_val(*pud)) {
326 phys_pmd_update(pud, addr, end);
327 continue;
328 }
329
330 pmd = alloc_low_page(&pmd_phys);
331
332 spin_lock(&init_mm.page_table_lock);
333 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
334 phys_pmd_init(pmd, addr, end);
335 spin_unlock(&init_mm.page_table_lock);
336
337 unmap_low_page(pmd);
338 }
339 __flush_tlb_all();
340 }
341
342 static void __init find_early_table_space(unsigned long end)
343 {
344 unsigned long puds, pmds, tables, start;
345
346 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
347 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
348 tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
349 round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
350
351 /*
352 * RED-PEN putting page tables only on node 0 could
353 * cause a hotspot and fill up ZONE_DMA. The page tables
354 * need roughly 0.5KB per GB.
355 */
356 start = 0x8000;
357 table_start = find_e820_area(start, end, tables);
358 if (table_start == -1UL)
359 panic("Cannot find space for the kernel page tables");
360
361 table_start >>= PAGE_SHIFT;
362 table_end = table_start;
363
364 early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
365 end, table_start << PAGE_SHIFT,
366 (table_start << PAGE_SHIFT) + tables);
367 }
368
369 /*
370 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
371 * This runs before bootmem is initialized and gets pages directly from
372 * the physical memory. To access them they are temporarily mapped.
373 */
374 void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
375 {
376 unsigned long next;
377
378 pr_debug("init_memory_mapping\n");
379
380 /*
381 * Find space for the kernel direct mapping tables.
382 *
383 * Later we should allocate these tables in the local node of the
384 * memory mapped. Unfortunately this is done currently before the
385 * nodes are discovered.
386 */
387 if (!after_bootmem)
388 find_early_table_space(end);
389
390 start = (unsigned long)__va(start);
391 end = (unsigned long)__va(end);
392
393 for (; start < end; start = next) {
394 pgd_t *pgd = pgd_offset_k(start);
395 unsigned long pud_phys;
396 pud_t *pud;
397
398 if (after_bootmem)
399 pud = pud_offset(pgd, start & PGDIR_MASK);
400 else
401 pud = alloc_low_page(&pud_phys);
402
403 next = start + PGDIR_SIZE;
404 if (next > end)
405 next = end;
406 phys_pud_init(pud, __pa(start), __pa(next));
407 if (!after_bootmem)
408 set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
409 unmap_low_page(pud);
410 }
411
412 if (!after_bootmem)
413 mmu_cr4_features = read_cr4();
414 __flush_tlb_all();
415
416 reserve_early(table_start << PAGE_SHIFT, table_end << PAGE_SHIFT);
417 }
418
419 #ifndef CONFIG_NUMA
420 void __init paging_init(void)
421 {
422 unsigned long max_zone_pfns[MAX_NR_ZONES];
423
424 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
425 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
426 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
427 max_zone_pfns[ZONE_NORMAL] = end_pfn;
428
429 memory_present(0, 0, end_pfn);
430 sparse_init();
431 free_area_init_nodes(max_zone_pfns);
432 }
433 #endif
434
435 /*
436 * Unmap a kernel mapping if it exists. This is useful to avoid
437 * prefetches from the CPU leading to inconsistent cache lines.
438 * address and size must be aligned to 2MB boundaries.
439 * Does nothing when the mapping doesn't exist.
440 */
441 void __init clear_kernel_mapping(unsigned long address, unsigned long size)
442 {
443 unsigned long end = address + size;
444
445 BUG_ON(address & ~LARGE_PAGE_MASK);
446 BUG_ON(size & ~LARGE_PAGE_MASK);
447
448 for (; address < end; address += LARGE_PAGE_SIZE) {
449 pgd_t *pgd = pgd_offset_k(address);
450 pud_t *pud;
451 pmd_t *pmd;
452
453 if (pgd_none(*pgd))
454 continue;
455
456 pud = pud_offset(pgd, address);
457 if (pud_none(*pud))
458 continue;
459
460 pmd = pmd_offset(pud, address);
461 if (!pmd || pmd_none(*pmd))
462 continue;
463
464 if (!(pmd_val(*pmd) & _PAGE_PSE)) {
465 /*
466 * Could handle this, but it should not happen
467 * currently:
468 */
469 printk(KERN_ERR "clear_kernel_mapping: "
470 "mapping has been split. will leak memory\n");
471 pmd_ERROR(*pmd);
472 }
473 set_pmd(pmd, __pmd(0));
474 }
475 __flush_tlb_all();
476 }
477
478 /*
479 * Memory hotplug specific functions
480 */
481 void online_page(struct page *page)
482 {
483 ClearPageReserved(page);
484 init_page_count(page);
485 __free_page(page);
486 totalram_pages++;
487 num_physpages++;
488 }
489
490 #ifdef CONFIG_MEMORY_HOTPLUG
491 /*
492 * Memory is added always to NORMAL zone. This means you will never get
493 * additional DMA/DMA32 memory.
494 */
495 int arch_add_memory(int nid, u64 start, u64 size)
496 {
497 struct pglist_data *pgdat = NODE_DATA(nid);
498 struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
499 unsigned long start_pfn = start >> PAGE_SHIFT;
500 unsigned long nr_pages = size >> PAGE_SHIFT;
501 int ret;
502
503 init_memory_mapping(start, start + size-1);
504
505 ret = __add_pages(zone, start_pfn, nr_pages);
506 WARN_ON(1);
507
508 return ret;
509 }
510 EXPORT_SYMBOL_GPL(arch_add_memory);
511
512 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
513 int memory_add_physaddr_to_nid(u64 start)
514 {
515 return 0;
516 }
517 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
518 #endif
519
520 #endif /* CONFIG_MEMORY_HOTPLUG */
521
522 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
523 kcore_modules, kcore_vsyscall;
524
525 void __init mem_init(void)
526 {
527 long codesize, reservedpages, datasize, initsize;
528
529 pci_iommu_alloc();
530
531 /* clear_bss() already clear the empty_zero_page */
532
533 /* temporary debugging - double check it's true: */
534 {
535 int i;
536
537 for (i = 0; i < 1024; i++)
538 WARN_ON_ONCE(empty_zero_page[i]);
539 }
540
541 reservedpages = 0;
542
543 /* this will put all low memory onto the freelists */
544 #ifdef CONFIG_NUMA
545 totalram_pages = numa_free_all_bootmem();
546 #else
547 totalram_pages = free_all_bootmem();
548 #endif
549 reservedpages = end_pfn - totalram_pages -
550 absent_pages_in_range(0, end_pfn);
551 after_bootmem = 1;
552
553 codesize = (unsigned long) &_etext - (unsigned long) &_text;
554 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
555 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
556
557 /* Register memory areas for /proc/kcore */
558 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
559 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
560 VMALLOC_END-VMALLOC_START);
561 kclist_add(&kcore_kernel, &_stext, _end - _stext);
562 kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
563 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
564 VSYSCALL_END - VSYSCALL_START);
565
566 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
567 "%ldk reserved, %ldk data, %ldk init)\n",
568 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
569 end_pfn << (PAGE_SHIFT-10),
570 codesize >> 10,
571 reservedpages << (PAGE_SHIFT-10),
572 datasize >> 10,
573 initsize >> 10);
574 }
575
576 void free_init_pages(char *what, unsigned long begin, unsigned long end)
577 {
578 unsigned long addr;
579
580 if (begin >= end)
581 return;
582
583 /*
584 * If debugging page accesses then do not free this memory but
585 * mark them not present - any buggy init-section access will
586 * create a kernel page fault:
587 */
588 #ifdef CONFIG_DEBUG_PAGEALLOC
589 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
590 begin, PAGE_ALIGN(end));
591 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
592 #else
593 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
594
595 for (addr = begin; addr < end; addr += PAGE_SIZE) {
596 ClearPageReserved(virt_to_page(addr));
597 init_page_count(virt_to_page(addr));
598 memset((void *)(addr & ~(PAGE_SIZE-1)),
599 POISON_FREE_INITMEM, PAGE_SIZE);
600 free_page(addr);
601 totalram_pages++;
602 }
603 #endif
604 }
605
606 void free_initmem(void)
607 {
608 free_init_pages("unused kernel memory",
609 (unsigned long)(&__init_begin),
610 (unsigned long)(&__init_end));
611 }
612
613 #ifdef CONFIG_DEBUG_RODATA
614 const int rodata_test_data = 0xC3;
615 EXPORT_SYMBOL_GPL(rodata_test_data);
616
617 void mark_rodata_ro(void)
618 {
619 unsigned long start = (unsigned long)_stext, end;
620
621 #ifdef CONFIG_HOTPLUG_CPU
622 /* It must still be possible to apply SMP alternatives. */
623 if (num_possible_cpus() > 1)
624 start = (unsigned long)_etext;
625 #endif
626
627 #ifdef CONFIG_KPROBES
628 start = (unsigned long)__start_rodata;
629 #endif
630
631 end = (unsigned long)__end_rodata;
632 start = (start + PAGE_SIZE - 1) & PAGE_MASK;
633 end &= PAGE_MASK;
634 if (end <= start)
635 return;
636
637 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
638
639 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
640 (end - start) >> 10);
641
642 rodata_test();
643
644 #ifdef CONFIG_CPA_DEBUG
645 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
646 set_memory_rw(start, (end-start) >> PAGE_SHIFT);
647
648 printk(KERN_INFO "Testing CPA: again\n");
649 set_memory_ro(start, (end-start) >> PAGE_SHIFT);
650 #endif
651 }
652 #endif
653
654 #ifdef CONFIG_BLK_DEV_INITRD
655 void free_initrd_mem(unsigned long start, unsigned long end)
656 {
657 free_init_pages("initrd memory", start, end);
658 }
659 #endif
660
661 void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
662 {
663 #ifdef CONFIG_NUMA
664 int nid = phys_to_nid(phys);
665 #endif
666 unsigned long pfn = phys >> PAGE_SHIFT;
667
668 if (pfn >= end_pfn) {
669 /*
670 * This can happen with kdump kernels when accessing
671 * firmware tables:
672 */
673 if (pfn < end_pfn_map)
674 return;
675
676 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
677 phys, len);
678 return;
679 }
680
681 /* Should check here against the e820 map to avoid double free */
682 #ifdef CONFIG_NUMA
683 reserve_bootmem_node(NODE_DATA(nid), phys, len);
684 #else
685 reserve_bootmem(phys, len);
686 #endif
687 if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
688 dma_reserve += len / PAGE_SIZE;
689 set_dma_reserve(dma_reserve);
690 }
691 }
692
693 int kern_addr_valid(unsigned long addr)
694 {
695 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
696 pgd_t *pgd;
697 pud_t *pud;
698 pmd_t *pmd;
699 pte_t *pte;
700
701 if (above != 0 && above != -1UL)
702 return 0;
703
704 pgd = pgd_offset_k(addr);
705 if (pgd_none(*pgd))
706 return 0;
707
708 pud = pud_offset(pgd, addr);
709 if (pud_none(*pud))
710 return 0;
711
712 pmd = pmd_offset(pud, addr);
713 if (pmd_none(*pmd))
714 return 0;
715
716 if (pmd_large(*pmd))
717 return pfn_valid(pmd_pfn(*pmd));
718
719 pte = pte_offset_kernel(pmd, addr);
720 if (pte_none(*pte))
721 return 0;
722
723 return pfn_valid(pte_pfn(*pte));
724 }
725
726 /*
727 * A pseudo VMA to allow ptrace access for the vsyscall page. This only
728 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
729 * not need special handling anymore:
730 */
731 static struct vm_area_struct gate_vma = {
732 .vm_start = VSYSCALL_START,
733 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
734 .vm_page_prot = PAGE_READONLY_EXEC,
735 .vm_flags = VM_READ | VM_EXEC
736 };
737
738 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
739 {
740 #ifdef CONFIG_IA32_EMULATION
741 if (test_tsk_thread_flag(tsk, TIF_IA32))
742 return NULL;
743 #endif
744 return &gate_vma;
745 }
746
747 int in_gate_area(struct task_struct *task, unsigned long addr)
748 {
749 struct vm_area_struct *vma = get_gate_vma(task);
750
751 if (!vma)
752 return 0;
753
754 return (addr >= vma->vm_start) && (addr < vma->vm_end);
755 }
756
757 /*
758 * Use this when you have no reliable task/vma, typically from interrupt
759 * context. It is less reliable than using the task's vma and may give
760 * false positives:
761 */
762 int in_gate_area_no_task(unsigned long addr)
763 {
764 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
765 }
766
767 const char *arch_vma_name(struct vm_area_struct *vma)
768 {
769 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
770 return "[vdso]";
771 if (vma == &gate_vma)
772 return "[vsyscall]";
773 return NULL;
774 }
775
776 #ifdef CONFIG_SPARSEMEM_VMEMMAP
777 /*
778 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
779 */
780 int __meminit
781 vmemmap_populate(struct page *start_page, unsigned long size, int node)
782 {
783 unsigned long addr = (unsigned long)start_page;
784 unsigned long end = (unsigned long)(start_page + size);
785 unsigned long next;
786 pgd_t *pgd;
787 pud_t *pud;
788 pmd_t *pmd;
789
790 for (; addr < end; addr = next) {
791 next = pmd_addr_end(addr, end);
792
793 pgd = vmemmap_pgd_populate(addr, node);
794 if (!pgd)
795 return -ENOMEM;
796
797 pud = vmemmap_pud_populate(pgd, addr, node);
798 if (!pud)
799 return -ENOMEM;
800
801 pmd = pmd_offset(pud, addr);
802 if (pmd_none(*pmd)) {
803 pte_t entry;
804 void *p;
805
806 p = vmemmap_alloc_block(PMD_SIZE, node);
807 if (!p)
808 return -ENOMEM;
809
810 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
811 PAGE_KERNEL_LARGE);
812 set_pmd(pmd, __pmd(pte_val(entry)));
813
814 printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
815 addr, addr + PMD_SIZE - 1, p, node);
816 } else {
817 vmemmap_verify((pte_t *)pmd, node, addr, next);
818 }
819 }
820 return 0;
821 }
822 #endif
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